Traffic tunnel and method of tunnel ventilation



sept. 9, 1947.

O. slNGsTAD ET Al.

TRAFFIC vTUNJEIJ-AND METHOD OF TUNNEL VENTILTION Filed July 1l, 1944 atented Sept. 9, 1947 TRAFFIC TUNNEL AND METHOD F TUNNEL VENTILATION Ole Singstad, New York, and Herbert G. Cruthers, Shokan, N. Y.

Application July 11, 1944., Serial No. 544,430

'7 Claims.

1 This invention is for an improved method or system for Ventilating trailic tunnels, and also for a novel and improved type of tunnel construction. In traine tunnels, which are used almost eximportance that a suitable amount of fresh air be supplied at all times to the various parts of the tunnel and that the smoke and combustion gases from the vehicles (containing poisonous carbon monoxide) be exhausted as quickly as possible.

In cylindrical, subaqueous tunnels, such, for example, as the Holland Tunnel in New York city, it is the accepted practice to make use of the top and bottom portions of the cylinder to provide two ducts, one beneath the roadway for supplying fresh air and the other in the roof over the ceiling of the roadway for exhausting said smoke and combustion gases.

However, the cost of excavating a cylindrical tunnel or other type of two-duct tunnel through a hill or mountain would be high as compared with the cost of constructing a tunnel having a at iloor or roadway, because of the additional amount of rock and earth required to be removed for the construction of a duct beneath the roadway corresponding to the lower duct of a cylindrical tunnel. According to the present invention, it is possible to achieve adequate ventilation of a tunnel by the provision of dual purpose Ventilating ducts located over or alongside the roadway. It is an important feature of our invention, therefore, not only to provide dual purpose, Ventilating ducts without excavating beneath the roadway, but also to provide means for using these ducts separately or together for forcing air into the tunnel or for exhausting the gas and smoke from the tunnel, as conditions require and as hereinafter described.

In the tunnel of the present invention, gases tunnel through the adjacent Ventilating duct,

used as an exhaust duct.

More specically, the tunnel of the present invention is ventilated by a Ventilating duct extending for the length of the tunnel; however, this duct is divided into two parts, and each part may be used to exhaust gases from its section of the tunnel, or to supply fresh air to its section of the tunnel, as may be necessary or desirabe, suitable means being provided for reversing the air flow in the ducts, as will be described. In that section of the` tunnel subjected to exhaust, fresh air enters the tunnel roadway at the adjacent mouth of the tunnel; in that section of the tunnel where fresh air is supplied by means of the duct, the exhaust gases pass out of the tunnel roadway at the other mouth thereof,

are exhausted from one section of the tunnel l roadway through a duct, fresh air entering the roadway at one end of the tunnel; the second or remaining section of the tunnel has fresh air supplied thereto by its Ventilating duct, the gases being exhausted through the roadway at the other end of the tunnel. However, the air flow in either duct may -be reversed, and this feature is especially important in the case of re. If a fire should occur in the tunnel, especially in that section where fresh air is coming into the tunnel from the duct, such incoming air would spread the smoke all through the tunnel driveway; accordingly, the air iiow should be immediately reversed in such a section and the smoke and gases from the re would then be carried out of the trame.

The tunnel of the present invention will handle one-way traffic or two-way traic. Where the tunnel is handling one-way traffic, the entrance section would be subject to exhaust, and fresh air would enter with the traffcythe second or exit section would be supplied with fresh air by means of the duct and the gases would leave the roadway at the other end of the tunnel. The direction of air flow would be inthe same general direction as the flow of tra'ic in both parts of the tunnel.

This same system would also handle two-way However, with two-way traflic, both ventilating ducts could be used as exhaust conduits, in which case fresh air would enter the tunnel at both ends and iiow toward the mid-portion of the tunnel, the exhaust gases being carriedaway by the exhaust ducts; or one duct could be used as an exhaust conduit and the other as a blower, air entering at one end of the tunnel driveway being exhausted at the other end thereof.

The invention will now be further described in more detail in connection with the accompanying drawings illustrating, more or less diagrammatically, how the invention may be practiced.

In these drawings:

Fig. 1 is a vertical longitudinal section of the tunnel of the present invention, diagrammatically illustrating its main features;

Fig. 2 is'a transverse cross section of the tunnel, on line 2 2 of Fig. 1;

Fig. 3 is a fragmentary plan view, on line 3-3 of Fig. 2; and

Figml is a vertical longitudinal section of the tunnel, showing another way of carrying out the invention.

Referring now to these drawings, the traffic tunnel 2 comprises a roadway 4 and a roof or ceiling V6. Extending lengthwise of the tunnel, conveniently in the roof thereof, is a ventilating duct 8 and a second Ventilating duct I0, the two ducts being defined by the partition or bulkhead I2 and being preferably coaxial. The roof or ceiling 6 of the tunnel is provided With openings I4 connecting the tunnel with the Ventilating ducts 'and Ill." While the Ventilating ducts are shown in the roof, it should be understood that any other suitable location could be used.

Ventilating duct 8 communicates with any suitable means for exhausting air from the duct or for supplying fresh air to the duct, as may be desired. For example, duct 8 may communicate with a fan housing I6 provided with a propeller type of fan I8 driven by a motor 20. As shown in Fig. 1f, this fan is operating as an exhaust fan, exhausting air from that section of the tunnel between one end 22 of the tunnel, and the partition I2. I'In order to reverse the air flow and cause the fan I8 to supply fresh air to this same section of the tunnel, the fan blades may be reversed, the Vdirection of rotation of the motor 2i) may be reversed, or a reversing gear' couldbe used between the motor and the fan, as will readily be understood by one skilled in the art.

A similar fan assembly is installed near the other end 24 of the tunnel, corresponding parts being indicated by primed reference characters. However, inr the right hand section of the tunnel, the fan I8' is shownas operating as a blower or pressure fan for supplying fresh air to duct I and thence to the tunnel in that, section between partition I2 and the other end 24 of the tunnel.

Assuming that cars are entering the left hand end 22 ofthe tunnel, the combustion gases given off by the cars will be drawn off through the exhaust duct 8 and out of the fan housing I6. This exhausting of the air through the roof of thetunnel will draw in fresh air at the entrance 22 'of the tunnel, and this fresh air will move along in the same general direction as the traffic. `That section of th'e'tunnel from the partition I2 to the other end 24 is supplied with fresh air from the fan I.8 'through the duct I0 and the openings I4 in the roof of the tunnel, this fresh air moving along with the cars in the general direction ofv the traffic, the gasesbeing delivered toY the atmosphere through the right hand end 24 of the tunnel.

The tunnel just described could be used. for eitherv one-way or two-way traffic. If used for one-way traffic, theV generalv direction ofr flow of the fresh air coming in at the left hand. end, through the mouth of the tunnel, and the general direction of flow of the fresh air coming in through the roof of the tunnel, in the right hand end, are both in the general. direction of. the flow of traffic.

Ifthe tunnel is handling two-way traffic, one lane would be travelling with the incoming fresh air, while the other lane would be going against the incoming fresh air, but in each casefresh air is being supplied and. the combustion gases are being carried out of the tunnel, so` that the harmful gases never exceedl safe limits. Similarly, in the right hand section ofthe tunnel, one lane of traffic would be travelling with the fresh airthat has come Vin`from the duct I0- and is moving out towardlthe mouth 24, while the other lane of traffic would be travelling more or less against thisA air, butin any case the Ycars would be supplied with the proper amount of fresh air.

and the combustion gases would bev carriedoutl of the end 24. 'If desired, both ducts -'and I0 could be used as exhaust conduits, by operating the fans in the proper direction, in which case fresh air would enter the tunnel at each end and flow inwardly, the exhaust gases being carried out the roof through the ducts 8 and I0.

An important feature of this invention lies in the provision of means whereby the air flow in either Ventilating duct may be quickly reversed. This feature is of particular value in case of fire, as already stated, and as experience with tunnel ventilation has demonstrated. If, for example, a iire should occur in the right hand section of the tunnel below the duct I0, the air flow in duct IU could be quickly reversed and the smoke and flames thereby exhausted through the roof of the tunnel and out through fan housing I6. If, on the other hand, a re should occur in that section of the tunnel below the duct 8, the normal exhaust through the roof would take care of the smoke and flames in that section; and, finally, if the fire were to occur near the partition I2, it would be possible quickly to reverse the air flow in duct I0 and thus carry away any smoke and flames that reach over into that section of the tunnel. In short, our improved method of ventilation is completely flexible and capable of meeting all contingencies successfully.

Another advantage of being able to reverse the flow in the ducts 8 and I0 is this: If the tunnel shown in Fig. 1 is for one-way traffic from left to right, the air flow would be as indicated, 8 acting as an exhaust duct and I0 as a fresh air duct, and the air flow would be in the same general direction as the traffic flow; however, if it should be necessary or advisable to have this tunnel carry one-way traffic in the opposite direction-that is, from right to leftthe air flow in the two ducts would be reversed, I0 becoming an exhaust duct and 8 a pressure duct, in which case the general direction of air flow in both sections of the tunnel would still be in the same direction as the traiiic flow.

In actual practice, it is proposed to use both an exhaust fan and a fresh air fan for each section ofv the tunnel, as shown in Fig. 4, the reversingV of the air flow being accomplished by shutting oione fan and operating the other, and. by providing suitable, dampers for connecting the Ventilating ducts with one fan or the other.

Referring now to Fig. 4, conduit 8 connects with a passage Y(Si), communicating either with housing 32 for a. pressure fan 36, or with afhousing 38 for an exhaust fan 4U, these fans being of vany desired type and driven byfany suitable type of motors or engines 42. A movable damper 44 pivoted at 46- at the lower edge of the partition 48 between the. fan housings can assume either oftwo positions against the stops 49y and 5I).v for respectively connecting the exhaust fan or the freshi'air fan, as the case may be, with the conduit'. As shown in Fig. 4, the exhaust fan 40- sfconnected` with the` conduit 8, and its .motor wouldJlbe running, while the fresh air fan 36 is shut off from conduit 8y and its motor wouldfbe stopped. 'Ifo' reverse the air flow, the motor for Efan 40 would. be stopped,V the` motor for fan 39 wouldA be started, Vand thedamperA shifted to.. connect fany 3.6' with conduit 8.

A precisely similar. arrangement isshown at the other endlofthetunnel, andcorresponding parts are indicated. by primed; reference 'characters However; at-theright-hand endvof Fig. 4 the' fresh air fan` is operating4 and, is in communication with the duct l D, while the exhaust fan is stopped and is shut off from the conduit by damper 44. The air flow is reversed by stopping one motor and starting the other and by shifting the damper 14' to the other position.

The air flow in the tunnel is as described in connection with Fig. l; namely, one section, the section shown at the left, is supplied with fresh air coming in through the mouth 22 of the tun-` nel, while smoke and combustion gases are drawn off through the roof by conduit 8. In the other section of the tunnel, fresh air comes in through the conduit l0, thence into the tunnel, and the smoke, air and combustion gases leave the tunnel at the end 2li. The air ow in either conduit 8 or IIJ may be reversed simply by shifting the damper 44 or 44 to the other position and by starting up one fan and shutting down the other.

It will, of course, be understood that in large tunnels or duplicate, side-by-side tunnels, several exhaust fans and several pressure fans may be used at each end of the tunnel, in installations duplicating the installations described herein, as may be required to supply suicient cubic feet of air per minute, in accordance with the number of cars and trucks that the tunnel is designed to handle.

The tunnel construction, and the method of tunnel ventilation, of the present invention, are of general application, and may be used in other types of tunnels, such, for example, as subways and railway tunnels.

Various details of construction and operation, which will be readily understood by those skilled in the art, are not shown in detail in the drawings, which, as has been said, are largely diagrammatic.

While the preferred ways of carrying out the invention have been illustrated, it should be understood that the disclosure is illustrative and not restrictive of the invention, and that it may be carried out in other ways.

We claim as our invention;

1. A traffic tunnel, provided with a pressure duct and an exhaust duct, both located in the upper portion of the tunnel, each duct extending only for a portion of the length of the tunnel and each being in communication with its adjacent portion of the tunnel, the two ducts together extending for substantially the full length of the tunnel, said ducts being independent of each other, whereby air under pressure in the pressure duct cannot flow through into the exhaust duct, means for supplying air under pressure to said pressure duct, and means for exhausting air and gases from said exhaust duct.

2. A trafc tunnel, provided with a pressure duct and an exhaust duct, both located in the upper portion of the tunnel, each duct extending only for a portion of the length of the tunnel and each being in communication with its adjacent portion of the tunnel, the two ducts together extending for substantially the full length of the tunnel, said ducts being independent of each other, whereby air under pressure in the pressure duct cannot flow through into the exhaust duct, means for supplying air under pressure to said pressure duct, means for exhausting air and gases from said exhaust duct, and means for effecting a reversal of gas ow in said pressure duct, whereby, in the event of fire or other necessity, gas and smoke can be exhausted through this duct.

3. In a traffic tunnel which is provided with independent pressure and exhaust Ventilating ducts in the upper part thereof, each duct ex- 7 tending only for a portion of the length of the tunnel and each duct being in communication with its adjacent portion of the tunnel, the method of Ventilating such a tunnel, comprising exhausting gas and air from one section of the tunnel through the exhaust duct, thereby causing fresh air to ow into this section of the tunnel through the adjacent open end thereof, and supplying fresh air under pressure to the other section of the tunnel through the pressure duct, thereby causing air and gas in said other section to pass out of the tunnel through the other open end thereof.

4. The method as set forth in claim 3, comprising the additional step of reversing the air flow in the pressure duct in the event of re or other necessity in the adjacent portion of the tunnel.

5. In a traflic tunnel which is provided with independent pressure eand exhaust Ventilating ducts in the upper part thereof, each duct extending only for a portion of the length of the tunnel and each duct being in communication with its adjacent portion of the tunnel, the method of Ventilating such a tunnel, where the tunnel is handling one way trahie, comprising exhausting air and gas from that section of the tunnel handling entering traffic, through said exhaust Ventilating duct, fresh air meanwhile entering the tunnel with such traic, and supplying fresh air under pressure to the other section of the tunnel, through which trafc leaving the tunnel is passing, the air and exhaust gas meanwhile leaving the tunnel with the traffic leaving the tunnel, the flow of air and gas in both sections of the tunnel being in the same general direction as the ow of trafc in both of said sections of the tunnel.

6. The method as set forth in claim 5, comprising the additional step of reversing the air flow in the pressure duct in the event of re or other necessity in the adjacent section of the tunnel.

7. A traic tunnel, comprising independent ventilating ducts, each located in the upper portion of the tunnel and each extending only for a portion of the length of the tunnel and each being in communication with its adjacent portion of the tunnel, said ducts being independent of each other, whereby air under pressure in the pressure duct cannot flow through into the exhaust duct, a pair of fans, one a pressure fan and the other an exhaust fan, positioned near each end of the tunnel, in cooperative relation with the ventilating duct at that end of the tunnel, the fans of a given pair of fans being alternately operable, so that only one fan of each pair is operated at a time, and means including dampers for selectively connecting one of each pair of fans to the adjacent Ventilating duct.

OLE SINGSTAD. HERBERT G. CRUTHERS.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS 

